Installation and method for supplying a fuel cell with hydrogen

ABSTRACT

An installation for supplying a fuel cell with hydrogen comprising a fuel cell, a liquefied hydrogen storage facility and a supply circuit that includes at least one upstream end connected to the storage facility and one downstream end connected to a fuel inlet of the fuel cell, the supply circuit including at least one system for heating hydrogen by heat exchange with a heat source and a set of control valves, the liquefied hydrogen storage facility being configured to keep the liquefied hydrogen in equilibrium with a gaseous phase at a determined nominal storage pressure of between 1.5 and 4.5 bar, the supply circuit including a buffer tank for pressurized gaseous hydrogen which is configured to store the hydrogen withdrawn from the storage facility and heated by the heating system, the set of valves being configured to accumulate pressurized gas in the buffer tank at a determined storage pressure of between 4 and 100 bar, for example between 6 and 8 bar.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119(a) and (b) to French patent application No. FR 2 002 892, filed Mar.25, 2020, the entire contents of which are incorporated herein byreference.

BACKGROUND Field of the Invention

The invention relates to an installation and a method for supplying afuel cell with hydrogen.

The invention relates more particularly to an installation for supplyinga fuel cell with hydrogen, the installation comprising a fuel cell, aliquefied hydrogen storage facility and a supply circuit comprising atleast one upstream end connected to the storage facility and onedownstream end connected to a fuel inlet of the fuel cell, the supplycircuit comprising at least one system for heating hydrogen by heatexchange with a heat source and a set of control valves, the liquefiedhydrogen storage facility being configured to keep the liquefiedhydrogen in equilibrium with a gaseous phase at a determined nominalstorage pressure of between 1.5 and 4.5 bar.

Related Art

Fuel cells operate with a hydrogen pressure at the anode of a fewhundred millibar. However, fuel cell manufacturers in most cases specifypressures of the order of 5 bar to 10 bar at their supply limit. Thismakes it possible to provide this pressure level downstream of the lastexpansion stage before the inlet of the anode. This pressure upstream ofthe cell inlet makes it possible to have a gas reservoir (or pressurizedgas reserve) for managing the shutdown of the cell in the event ofunexpected stopping of the hydrogen supply. This is because, if thesupply of hydrogen is abruptly stopped while the power demand is stillpresent, without this pressurized hydrogen reserve, the hydrogen presentat the anode would be consumed which would lead to a negative relativepressure at this interface. This can damage the electrode membraneassembly of the cell (by inversion of the pressure with respect to thecathode and potentially placing the anode under a vacuum).

In the case of feeding hydrogen with pressurized gas storage facilities(350/700 bar), there is often a lower limit of operation of the tankswhich is fixed between 10 and 20 bar (for example in order to avoiddamaging the composite structure of the type 4 tanks with polymer liner,or to avoid reaching a pressure which is too close to atmosphericpressure in the tank, which would favour entry of humidity or of air).This low pressure level is compatible with the abovementioned reservespecification of 5 to 10 bar. In other configurations, the hydrogen isprovided by a liquid hydrogen cryogenic storage facility.

Liquid hydrogen storage facilities are generally kept at a relativelylow pressure for a number of reasons. Such a tank naturallyself-pressurizes via the thermal inputs (insulation, pipelines,supports) when no flow of product is withdrawn. There is thereforeinterest in storing the fluid at the lowest possible pressure in orderto maintain the greatest possible difference in pressure between theoperating pressure and the set pressure of the valve; specifically, thismakes it possible to increase the endurance of the storage facility(increased duration before an overpressure valve opens). In addition,liquid hydrogen expands as its liquid/gas saturation pressure increases.A gas headspace of the order of 5% (in moles) should be maintained atthe opening of the valve. Thus, the more elevated the pressure of avalve opening in a storage facility, the less it can be filled at its(relatively low) filling pressure.

Lastly, the latent heat of vaporization of the hydrogen decreases as afunction of the liquid/vapour saturation pressure. Since the rate ofincrease in pressure in the self-pressurization phase is inverselyproportional to this latent heat, the pressure of a cryogenic storagefacility increases all the faster when this pressure is high (convexcurve of the rise in self-pressurization).

In the case where fuel cells are operated at high pressure (for exampleat 6 bar) and where the hydrogen tank which feeds the cell is alow-pressure (for example 2.5 bar abs.) liquid storage facility, it isnecessary to self-pressurize the storage facility prior to starting upthe cell. This self-pressurization may consist in removing liquid fromthe storage facility and evaporating and reinjecting it into the gaseousphase of the storage facility. This leads to a deviation from thethermodynamic equilibrium of the storage facility via a temperaturestratification of the gas headspace.

If the tank is installed on board a train or boat, the gas headspacewill condense upon the first shock (or wave) and the tank will return toits equilibrium pressure, which might be located below the minimumoperating pressure of the fuel cell. In this configuration, in order toguarantee optimum operation of the cells, it is theoretically necessaryto arrange two liquid buffer tanks which are kept saturated between themain tank and the fuel cell. One tank is filled and pressurized whilethe other feeds the fuel cell. The tank has a volume sufficient for thepressurized tank to be at its equilibrium pressure when it is connectedto the cell. Such a device makes it possible to feed the cell withhydrogen at a sufficient pressure. This has the disadvantage ofrequiring two additional cryogenic tanks and a higher hydrogenconsumption, since the empty intermediate tank must be filled and hotand at high pressure and must be cooled and depressurized in order to berefilled with liquid hydrogen.

A specification of the hydrogen at 5 bar for a fuel cell use from aliquid storage facility thus penalizes the filling level of the storagefacility and its endurance.

For all of these reasons, there is instead interest in limiting theoperating pressure of the hydrogen at the outlet of the storage facilityto a pressure of the order of 2.5 to 3.5 bar abs., far below the 5 barspecified by the fuel cell manufacturers.

SUMMARY OF THE INVENTION

One aim of the present invention is to overcome all or some of thedisadvantages of the prior art noted above.

To this end, the installation according to the invention, moreover inaccordance with the generic definition given for it in the preambleabove, is essentially characterized in that the supply circuit includesa buffer tank for pressurized gaseous hydrogen which is configured tostore the hydrogen withdrawn from the storage facility and heated by theheating system, the set of valves being configured to accumulatepressurized gas in the buffer tank at a determined storage pressure ofbetween 4 and 100 bar, for example between 6 and 8 bar.

The invention thus makes it possible to operate a liquid hydrogenstorage facility at relatively low pressure while maintaining a reserveof hydrogen at higher pressure which is necessary in order to be able toensure safe shutdown of the fuel cell in the event of an unexpectedshutoff of the feed from the liquid storage facility. This reserve ofpressurized gaseous hydrogen can be automatically regenerated during thevarious life stages of the liquid storage facility, in particular duringthe self-pressurization phases, that is to say when the cell is shutdownand the pressure of the storage facility increases naturally due to theinputs of heat.

Furthermore, embodiments of the invention can comprise one or more ofthe following features:

-   -   the supply circuit comprises a liquid withdrawal pipe connecting        the lower portion of the storage facility to the fuel inlet of        the fuel cell, the liquid withdrawal pipe comprising, arranged        in series: a first heating heat exchanger, and a first pressure-        and/or flow rate-regulator, said first pressure- and/or flow        rate-regulating valve being configured to feed the fuel inlet of        the fuel cell at a determined operating pressure of between 1        and 3 bar,    -   the circuit comprises a gas withdrawal pipe connecting the upper        portion of the storage facility to an inlet of the buffer tank,    -   the gas withdrawal pipe comprises, arranged in series: a heat        exchanger for heating gaseous hydrogen, and a pressure- and/or        flow rate-regulating valve, said pressure- and/or flow        rate-regulating valve being configured to transfer gas at the        storage pressure into the buffer tank,    -   the pressure- and/or flow rate-regulating valve is configured to        automatically transfer gas from the storage facility to the        buffer tank only when the pressure in the storage facility        exceeds a determined pressure threshold,    -   the circuit comprises a gas filling pipe having an upstream end        connected to an outlet of the first heating heat exchanger and a        downstream end connected to an inlet of the buffer tank, the gas        filling pipe comprising a pressure- and/or flow rate-regulating        valve, said pressure and/or flow rate regulator being configured        to transfer gas at the storage pressure into the buffer tank,    -   the circuit comprises a liquid removal pipe having an upstream        end connected to the lower portion of the storage facility and a        downstream end connected to an inlet of the buffer tank,    -   the circuit comprises a set of isolation valves arranged at the        inlet and at the outlet of the buffer storage facility, the        hydrogen heating system comprising an exchange of heat between        the fluid contained in the buffer storage facility and a heat        source such as the atmosphere for vaporizing and increasing the        pressure of the fluid in the buffer tank when the isolation        valves are closed, the circuit furthermore comprising an element        for limiting the pressure in said buffer storage facility such        as a discharge valve which opens above a determined pressure        threshold,    -   the supply circuit comprises a backup feed pipe connecting an        outlet of the buffer tank to the fuel inlet of the fuel cell,        the backup feed pipe comprising at least one pressure- and/or        flow rate-regulating valve configured to provide gas at a        determined pressure to the cell,    -   the backup feed pipe comprises, arranged in series with the at        least one pressure- and/or flow rate-regulating valve: a valve        shutter, a heating heat exchanger, and a pressure-sensitive        safety valve for discharging the gas to the outside of the        circuit in the event of pressure above a safety threshold,    -   - the backup feed pipe is connected to the fuel inlet of the        fuel cell via a connection to a portion of the liquid withdrawal        pipe.

The invention also relates to a method for supplying a fuel cell withhydrogen using an installation according to any one of the featuresabove or below, wherein the fuel cell is fed with hydrogen by thestorage facility, the method comprising a step of transferring hydrogenfrom the storage facility to the buffer tank.

According to other possible distinguishing features:

-   -   the step of transferring hydrogen from the storage facility to        the buffer tank is performed during an interruption to the        feeding of the cell with hydrogen by the storage facility, in        particular during a shutdown of the fuel cell,    -   the method includes, during the operation of the fuel cell, a        step of detecting a fault in the feeding of the fuel cell with        hydrogen by the storage facility and, in response, a step of        backup feeding in which the fuel cell is fed with hydrogen by        the buffer tank.

The invention may also relate to any alternative device or methodcomprising any combination of the features above or below within thescope of the claims.

BRIEF DESCRIPTION OF THE FIGURES

Other distinctive features and advantages will become apparent onreading the description below, which is made with reference to thefigures, in which:

FIG. 1 represents a diagrammatic and partial view illustrating thestructure and the operation of a first implementational example of aninstallation according to the invention,

FIG. 2 represents a diagrammatic and partial view illustrating anexample of variations in a possible pressure within the cryogenicstorage facility of the installation,

FIG. 3 represents a diagrammatic and partial view illustrating thestructure and the operation of a second implementational example of aninstallation according to the invention,

FIG. 4 represents a diagrammatic and partial view illustrating thestructure and the operation of a third implementational example of aninstallation according to the invention,

FIG. 5 represents a diagrammatic and partial view illustrating thestructure and the operation of a fourth implementational example of aninstallation according to the invention,

FIG. 6 represents a diagrammatic and partial view illustrating thestructure and the operation of a fifth implementational example of aninstallation according to the invention,

FIG. 7 represents a diagrammatic and partial view illustrating thestructure and the operation of a sixth implementational example of aninstallation according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The installation 1 for supplying a fuel cell with hydrogen comprises afuel cell 2, a liquefied hydrogen storage facility 3 and a supplycircuit 4, 14 comprising at least one upstream end connected to thestorage facility 3 and one downstream end connected to a fuel inlet ofthe fuel cell 2.

The supply circuit 4, 14 comprises at least one system 5, 15 for heatinghydrogen by heat exchange with a heat source and a set of control valves6, 16, 26.

The liquefied hydrogen storage facility 3 is configured to keep theliquefied hydrogen in equilibrium with a gaseous phase at a relativelylow determined nominal storage pressure of for example between 1.5 and4.5 bar.

The supply circuit 4, 14 includes a buffer tank 7 for pressurizedgaseous hydrogen which is configured to store the hydrogen withdrawnfrom the storage facility 3 and heated by the heating system 5, 15. Theset of valves is configured to accumulate pressurized gas in the buffertank 7 at a relatively high determined storage pressure of between 4 and100 bar, for example between 6 and 8 bar.

The supply circuit comprises a liquid withdrawal pipe 4 connecting thelower portion of the storage facility 3 to the fuel inlet of the fuelcell 2.

The liquid withdrawal pipe 4 comprises, arranged in series: a firstheating heat exchanger 5 (or evaporator) and a first pressure- and/orflow rate-regulating valve 6. This first pressure- and/or flowrate-regulating valve 6 is configured to feed the fuel inlet of the fuelcell 2 at a determined operating pressure of for example between 1 and 3bar abs. This feeding with hydrogen from the liquid storage facility 3constitutes what is called normal operation, when the fuel cell 2 is inan operating state.

In the embodiment of FIG. 1, the circuit comprises a gas withdrawal pipe8 connecting the upper portion of the storage facility 3 to an inlet ofthe buffer tank 7. The gas withdrawal pipe 8 comprises, arranged inseries: a second heat exchanger 15 for heating gaseous hydrogen and asecond pressure- and/or flow rate-regulating valve 26. The second heatexchanger 15 is for example an atmospheric heater which brings theremoved gaseous hydrogen to a temperature of 22 K to 100 K.

The second pressure- and/or flow rate-regulating valve 26 is for itspart configured to transfer gas at the storage pressure, for examplebetween 5 and 8 bar, into the buffer tank 7.

The second pressure- and/or flow rate-regulating valve 26 (and/or anappropriate valve shutter system (not shown), for example at least onenon-return valve) may be configured to automatically transferpressurized gas from the storage facility 3 to the buffer tank 7,preferably only when the pressure in the storage facility 3 exceeds adetermined pressure threshold.

This is because, in particular in the phases in which the fuel cell 2 isnot fed by the storage facility 3 for relatively long periods, thestorage facility 3 has a tendency to self-pressurize. Its internalpressure can in particular reach thresholds of greater than 5 bar. Thispressure decreases as soon as hydrogen is withdrawn in the gasheadspace.

FIG. 2 illustrates an example of variations in pressure P (in bar) inthe storage facility 3 as a function of time t. As illustrated, thepressure can describe rising gradients in the case ofself-pressurization, for example, and falling gradients (in the case ofwithdrawal, for example). The second regulation valve 26 can for examplebe configured (regulated, dimensioned, calibrated or controlled) so asto open when the upstream pressure is greater than an opening threshold(for example 6 bar) and to close again when the upstream pressure isless than this opening threshold (or another pressure threshold).

This makes it possible to transfer, preferably automatically, gas fromthe storage facility 3 to the buffer tank 7, preferably only when thepressure in the storage facility 3 exceeds a determined pressurethreshold. In the embodiment of FIG. 3, the circuit comprises a gasfilling pipe 9 having an upstream end connected to an outlet of thefirst heating heat exchanger 5 and a downstream end connected to aninlet of the buffer tank 7. This gas filling pipe 9 comprises a secondpressure- and/or flow rate-regulating valve 26, said second pressure-and/or flow rate-regulating valve 26 being configured to transfer gas atthe storage pressure into the buffer tank 7 after said gas has passedthrough the first heating heat exchanger 5.

In other words, the filling of the buffer tank 7 can be controlled by anexpansion device 26 on a diversion line of the liquid withdrawal pipe 4,downstream of the first heating heat exchanger 5.

This expansion device 26 (or an equivalent valve or valve shutter, cf.below) can be activated in particular when the feeding of hydrogen tothe fuel cell 2 is shut off. In this case, the feeding of the fuel cell2 with gaseous hydrogen can be performed by the buffer tank 7 via adownstream third pressure- and/or flow rate-regulating valve 16 (theoutlet of which can be connected to the downstream portion of the liquidwithdrawal pipe 4 which is connected to the fuel inlet of the fuel cell2).

The embodiment of FIG. 4 differs from that of FIG. 3 in that theexpansion device 26 is replaced by a simple valve or valve shutter. Itshould be noted that, just as in the embodiment of FIG. 3, the inlet ofthe buffer tank 7 could be connected to the upper portion of the storagefacility 3 in order to recover the vaporization gas (instead of the gasobtained from the vaporization of the liquid in the heat exchanger 5).

The embodiment of FIG. 5 differs from that of FIG. 3 in that the inletand the outlet of the buffer tank 7 have been combined. The filling ofthe buffer tank 7 or the withdrawal of gas from the buffer tank 7 arecontrolled by a second regulation valve or valve shutter connected tothe liquid withdrawal pipe 4, for example downstream of the firstheating heat exchanger 5 and upstream of the first pressure- and/or flowrate-regulating valve 6.

The filling of the buffer tank 7 may in particular be controlled by thesecond valve 26 which can be automatically opened as soon as thepressure in the storage facility 3 is greater than a high threshold.This second valve 26 may also be automatically opened when the normalfeeding of the fuel cell 2 with hydrogen is shut off (for example due toa lack of liquid in the storage facility).

In the embodiment of FIG. 6, the circuit comprises a liquid removal pipe10 having an upstream end connected to the lower portion of the storagefacility 3 and a downstream end connected to an inlet of the buffer tank7. As illustrated, this liquid removal pipe 10 can be a diversion of theupstream portion of the liquid withdrawal pipe 4.

In this embodiment, the circuit comprises a set of isolation valves 11,12 arranged at the inlet and at the outlet of the buffer storagefacility 7. A possible heating of the hydrogen comprises an exchange ofheat between the fluid contained in the buffer storage facility 7 and aheat source such as the atmosphere for vaporizing and increasing thepressure of the fluid in the buffer tank 7 when the isolation valves 11,12 are closed and trap the fluid in the buffer tank 7. Moreover, thecircuit preferably additionally comprises an element 13 for limiting thepressure in said buffer storage facility 7 such as a discharge valveconnected to the tank 7 and opening above a determined pressurethreshold.

In this configuration, the buffer tank 7 can thus be filled withcryogenic liquid upstream of the first heating heat exchanger 5 via theopening of the upstream isolation valve 11 (and possibly the downstreamisolation valve 12). When the buffer tank 7 is filled and preferablycold (temperature for example of between 25 and 150 K), the isolationvalves 11, 12 can be closed. The trapped liquid will evaporate due tothe heat inputs (possibly also via active heating); the pressureincreases in the buffer tank 7. Any possible overpressure can bedischarged via the discharge valve 13 (which can remain closed duringfilling of the buffer tank 17 at constant pressure). The pressure in thebuffer tank 7 is for example brought to a value between 6 and 100 barand thus constitutes a reserve of pressurized hydrogen for feeding thefuel cell 2 in the event of failure of the normal feed (for example viathe opening of the downstream isolation valve 12).

The embodiment of FIG. 7 differs from that of FIG. 6 in that the inletof the buffer tank 7 is connected to the upper portion of the storagefacility 3 via a gas withdrawal pipe 8.

The filling of the buffer tank 7 can thus be performed upstream of thefirst heating heat exchanger 5 by opening the upstream isolation valve11 and possibly the second isolation valve 12. The buffer tank 7 isfilled with cold gas from the storage facility 3. The rest of theprocess can be identical to that described above in relation with FIG.6.

Thus, in the normal configuration the storage facility 3 can bemaintained at a relatively low pressure (less than 5 bar for example)and feeds the fuel cell 2 at a pressure of between 1 and 5 bar viaevaporation and regulation of pressure. A possible and temporaryoverpressure in the storage facility 3 can be used to fill the buffertank 7 at a higher pressure (5 bar or more for example). Thispressurized gas reserve 7 is usable for feeding the fuel cell 2 withhydrogen if the normal feed is unavailable. In the configurations ofFIG. 6 and FIG. 7, the pressure in the buffer tank 7 can be brought upto more than 200 bar by simple heating of the cold gas/liquid trapped inthe tank 7 while the valves 11 and 12 are closed. This makes it possibleto continue to feed the fuel cell 2 for example for the time it takesfor the pressurization system of the storage facility 3 to re-establishthe nominal operating pressure of the hydrogen.

The installation may thus take advantage of the self-pressurization(inactivated cell) use phases of the storage facility 3 during which thepressure in the storage facility 3 may rise to a pressure greater than 5bar for filling a buffer tank 7.

As illustrated in the non-limiting examples, the hydrogen used to fillthe buffer tank 7 may be removed directly at the gas headspace (upperportion of the storage facility), upstream and/or downstream of theheating heat exchanger(s) 5, 15.

While the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives,modifications, and variations will be apparent to those skilled in theart in light of the foregoing description. Accordingly, it is intendedto embrace all such alternatives, modifications, and variations as fallwithin the spirit and broad scope of the appended claims. The presentinvention may suitably comprise, consist or consist essentially of theelements disclosed and may be practiced in the absence of an element notdisclosed. Furthermore, if there is language referring to order, such asfirst and second, it should be understood in an exemplary sense and notin a limiting sense. For example, it can be recognized by those skilledin the art that certain steps can be combined into a single step.

The singular forms “a”, “an” and “the” include plural referents, unlessthe context clearly dictates otherwise.

“Comprising” in a claim is an open transitional term which means thesubsequently identified claim elements are a nonexclusive listing i.e.anything else may be additionally included and remain within the scopeof “comprising.” “Comprising” is defined herein as necessarilyencompassing the more limited transitional terms “consisting essentiallyof” and “consisting of”; “comprising” may therefore be replaced by“consisting essentially of” or “consisting of” and remain within theexpressly defined scope of “comprising”.

“Providing” in a claim is defined to mean furnishing, supplying, makingavailable, or preparing something. The step may be performed by anyactor in the absence of express language in the claim to the contrary.

Optional or optionally means that the subsequently described event orcircumstances may or may not occur. The description includes instanceswhere the event or circumstance occurs and instances where it does notoccur.

Ranges may be expressed herein as from about one particular value,and/or to about another particular value. When such a range isexpressed, it is to be understood that another embodiment is from theone particular value and/or to the other particular value, along withall combinations within said range.

All references identified herein are each hereby incorporated byreference into this application in their entireties, as well as for thespecific information for which each is cited.

What is claimed is:
 1. An installation for supplying a fuel cell withhydrogen, the installation comprising a fuel cell, a liquefied hydrogenstorage facility and a supply circuit comprising at least one upstreamend connected to the storage facility and one downstream end connectedto a fuel inlet of the fuel cell, the supply circuit comprising at leastone system for heating hydrogen by heat exchange with a heat source anda set of control valves, the liquefied hydrogen storage facility beingconfigured to keep the liquefied hydrogen in equilibrium with a gaseousphase at a determined nominal storage pressure of between 1.5 and 4.5bar, wherein the supply circuit further comprises a liquid withdrawalpipe and a buffer tank for pressurized gaseous hydrogen that isconfigured to store the hydrogen withdrawn from the storage facility andheated by the heating system, the set of valves being configured toaccumulate pressurized gas in the buffer tank at a determined storagepressure of between 4 and 100 bar, the liquid withdrawal pipe connectinga lower portion of the storage facility to the fuel inlet of the fuelcell, the liquid withdrawal pipe comprising, arranged in series, a firstheating heat exchanger and a first pressure- and/or flow rate-regulatingvalve, said first pressure- and/or flow rate-regulating valve beingconfigured to feed the fuel inlet of the fuel cell at a determinedoperating pressure of between 1 and 3 bar.
 2. The installation of claim1, wherein the circuit further comprises a gas withdrawal pipeconnecting an upper portion of the storage facility to an inlet of thebuffer tank.
 3. The installation of claim 2, wherein the gas withdrawalpipe comprises, arranged in series, a heat exchanger for heating gaseoushydrogen and a second pressure- and/or flow rate-regulating valve, saidsecond pressure- and/or flow rate-regulating valve being configured totransfer gas at the storage pressure into the buffer tank.
 4. Theinstallation of claim 3, wherein the second pressure- and/or flowrate-regulating valve is configured to automatically transfer gas fromthe storage facility to the buffer tank only when the pressure in thestorage facility exceeds a determined pressure threshold.
 5. Theinstallation of claim 1, wherein the circuit further comprises a gasfilling pipe having an upstream end connected to an outlet of the firstheating heat exchanger and a downstream end connected to an inlet of thebuffer tank, the gas filling pipe comprising a third pressure- and/orflow rate-regulating valve, said third pressure and/or flow rateregulator being configured to transfer gas at the storage pressure intothe buffer tank.
 6. The installation of claim 1, wherein the circuitfurther comprises a liquid removal pipe having an upstream end connectedto the lower portion of the storage facility and a downstream endconnected to an inlet of the buffer tank.
 7. The installation of claim2, wherein the circuit further comprises a set of isolation valvesarranged at the inlet and the outlet of the buffer storage facility, thehydrogen heating system comprising an exchange of heat between the fluidcontained in the buffer storage facility and a heat source such as theatmosphere for vaporizing and increasing the pressure of the fluid inthe buffer tank when the isolation valves are closed, the circuitfurthermore comprising an element for limiting the pressure in saidbuffer storage facility such as a discharge valve which opens above adetermined pressure threshold.
 8. The installation of claim 7, whereinthe heat source is the atmosphere.
 9. The installation of claim 1,wherein the supply circuit further comprises a backup feed pipeconnecting an outlet of the buffer tank to the fuel inlet of the fuelcell, the backup feed pipe comprising at least one fourth pressure-and/or flow rate-regulating valve configured to provide gas at adetermined pressure to the cell.
 10. The installation of claim 7,wherein the supply circuit further comprises a backup feed pipeconnecting an outlet of the buffer tank to the fuel inlet of the fuelcell, the backup feed pipe comprising at least one fourth pressure-and/or flow rate-regulating valve configured to provide gas at adetermined pressure to the cell and, arranged in series, a valveshutter, a heating heat exchanger, and a pressure-sensitive safety valvefor discharging the gas to the outside of the circuit in the event ofpressure above a safety threshold.
 11. The installation of claim 9,wherein the backup feed pipe is connected to the fuel inlet of the fuelcell via a connection to a portion of the liquid withdrawal pipe. 12.The installation of claim 1, wherein the set of valves is configured toaccumulate pressurized gas in the buffer tank at a determined storagepressure of between 6 and 8 bar
 13. A method for supplying a fuel cellwith hydrogen using the installation of claim 1, wherein the fuel cellis fed with hydrogen by the storage facility, the method comprising astep of transferring hydrogen from the storage facility to the buffertank.
 14. The method of claim 13, wherein the step of transferringhydrogen from the storage facility to the buffer tank is performedduring an interruption to the feeding of the cell with hydrogen by thestorage facility, in particular during a shutdown of the fuel cell. 15.The method of claim 13, wherein the step of transferring hydrogen fromthe storage facility to the buffer tank is performed during a shutdownof the fuel cell.
 16. The method of claim 13, further comprising, duringthe operation of the fuel cell, a step of detecting a fault in thefeeding of the fuel cell with hydrogen by the storage facility and, inresponse, a step of backup feeding in which the fuel cell is fed withhydrogen by the buffer tank.